There are probably an uncountable number of variables that go into role playing, and a lot of them depend on what type of role play you're in and what kind of character you are trying to depict. However, there are two fundamentals to all role playing that set the stage and determine the depth and breadth of where the imagination can go: Detail and Flow.

The first, and in my opinion most important, step to making your posts fun to write and read is to fill it up with Detail. Even the most boring sentence comes alive when filled with valuable and lush words that accurately describe the situation at hand. Even the most insignificant detail can turn out to be important, and the more information you and your role playing partners share, the more you can become immersed in the fantasy world that you're creating together. Take this sentence for example.

Tyler set his hand on the prisoner and spoke, "Who sent you? Tell me!"

Not a boring sentence, but fairly ordinary and nothing to make it stand out or pull in someone's attention. Whereas a post full of detail:

Tyler slammed his right hand down onto the already-bruised left shoulder of the captured ver'drowendar, his voice breaking slightly as his desperation for information began to show, "Who sent y-you? Tell me, you male-raised excuse for an elf!"

Perhaps not all sentences are as violently action-packed as this one, but even the most innocuous and laid-back post can be enriched and lengthened by an attention to surroundings and intimacies.

When it comes to detail, the most important thing one can describe is not your character itself, but the things around your character. Yes, it's good for everyone to know what your character is wearing, but it's more critical to explain how the dust puffs up around your character's feet than to know what kind of shoes he or she might have on. Let people know how the cold air causes you to draw your cloak tighter about you, how the smell from the pack animals causes you to wrinkle your nose in disgust, or how that rowdy group of bachelorettes at the other end of the bar is making it hard for your character to hear what's being said.

Finally, adjectives and details are not the same thing. Some people will tell you that adding adjectives to a sentence is the same thing as adding details, but that's maybe a quarter of the enhancements you can give it to make it really shine. Adjectives are useful, and have there place, but are by no means your only tool. A proper use of colorful nouns and verbs is far more powerful than simply throwing a few descriptive words on top of a bland sentence.

The second step to creating an enjoyable scene and bringing the characters to life is Flow. All you perverts get your mind out of the gutter, now. Flow, though less important in my opinion, is far more difficult to get right than detail. The flow of a post is when each action leads into the next one, and the whole thing seems like one solid thing rather than several small blocks. The biggest interruption to flow is the belief that each paragraph is about a separate subject. And, while that might be true in a five paragraph essay for your English class, that should not be how a post is written. The end of each paragraph or sentence should segue neatly into the other.

For example, if you're talking to one character in the first paragraph, and a second character in a second paragraph, then there should be a sentence or two in between the two conversations that explains how you get from one place to the other. So instead of doing this:

Tyler slammed his right hand down onto the already-bruised left shoulder of the captured ver'drowendar, his voice breaking slightly as his desperation for information began to show, "Who sent y-you? Tell me, you male-raised excuse for an elf!"

"The traitor is never going to divulge what she knows. We really should minimize the damage by acting quickly and shoring up our defenses, just in case," Tyler spat out his frustration to his superior officer, who stood off to the side glowering at the lack of results.

Try and blend it together like this:

Tyler slammed his right hand down onto the already-bruised left shoulder of the captured ver'drowendar, his voice breaking slightly as his desperation for information began to show, "Who sent y-you? Tell me, you male-raised excuse for an elf!" Without waiting for an answer, he straightened up and spat on the ground out of disgust for the would-be-assassin. Dragging the back of one gloved hand over his mouth to wipe away any spittle that clung to his lips, he shot a rough glance towards the third figure in the room.

"The traitor is never going to divulge what she knows. We really should minimize the damage by acting quickly and shoring up our defenses, just in case," Tyler spat out his frustration to his superior officer, who stood and glowered at the lack of results.

This applies to more than just conversations, of course, but it's the most common example of when people simply leave a gap where others are forced to wonder what happened in between. Again, I stress that it is best to write out every single thing that your character does. Don't let others wonder how you see your character in your head, show them in exquisite detail and you'll find them warming up to your character even faster and reciprocating by showing off their character in return.

Ultimately Detail and Flow are much the same thing, for they both require you to explain more than the bare bones of what you're doing. They require you to say more than 'he walked there', and to tell a story with rich and vivid light shone into every corner. They are the quintessential basis upon which good storytelling, and therefore good role playing, is based. For role plays such as this are not about numbers and skills and capabilities, they're about the ability to bring a scene to life with nothing but the force of words. May the force be with you.

I might note that simply adding a liberal dash of explosives and fire (ie: ACTION SEQUENCE) will NOT help. What is important is DETAIL for the CONTEXT. If you are in a fight scene, more detail is needed for combat sequences. While you are bartering, more detail is needed for the haggling.

Also, irony: It can be really funny if someone's character is nonchalantly buying slaves while there's a massive battle in the background IF this is done correctly. Problematically, unless you are really good (coughKerncough), it's more like that yur doin' eet wrong.